useless trivia: What Word Means: A Minnow?

Questions

In optics, property of a lens system of bending a beam of white light in such a way that all its component colors are brought to a focus at the same point, thus obtaining a sharp image?

In physics, devices used to accelerate charged elementary particles or ions to high energies?

In physics, mechanism by what energy is conveyed from one place to another in mechanically propagated waves without the transference of matter?

In physics, product of a force applied to a body & the displacement of the body in the direction of the applied force?

In popular usage, name denoting the acute disease known medically as aeroembolism & caused by rapid decrease of the atmospheric pressure?